The original building was expanded twice, in 1902 and 1913. After his death in 1932, the collection and building were bequeathed to the Village of Southampton but, without Parrish’s guiding vision, the Museum ceased to thrive. It wasn’t until the 1950s, under the direction of the newly elected president of the board of trustees, Rebecca Bolling Littlejohn,[3] that the Museum enjoyed its own renaissance. Recognizing the importance of this country’s contribution to the arts, Mrs. Littlejohn launched a campaign to strengthen the Museum’s holdings of American art, with special attention to artists associated with eastern Long Island such as Thomas Moran, Childe Hassam, and Thomas Doughty. Upon her death, the Museum became the beneficiary of more than 300 paintings, drawings, and watercolors from her personal collection, which included work by Martin Johnson Heade, Asher B. Durand, John H. Twachtman, John Sloan, and a remarkable collection of thirty-one paintings by American ImpressionistWilliam Merritt Chase.

In 1981, further depth was added to the collection when nearly 200 works of art by the prominent American painter, critic, and longtime Southampton resident Fairfield Porter (1907–1975) were donated by his wife Anne and by the artist’s estate. Building from the strength of these collections, the Museum now traces the evolution of American art from its roots in an emerging landscape tradition through the liberating influences of European modernism and the development of the New York School to the stylistic diversity of contemporary art, focusing its exhibitions and acquisitions on American painting of the twentieth and twenty-first centuries, with special attention to artists who have lived and worked on Long Island’s East End and their influence on the national and international art world. Once home to Jackson Pollock, Willem de Kooning, and Roy Lichtenstein, among many others, today’s residents, full-time or seasonal, include Chuck Close, Ross Bleckner, April Gornik, Eric Fischl, Ilya and Emilia Kabakov, and Donald Sultan.[3]

The museum had long had a significant amount of its collection in storage. It 2000 it acquired the neighboring Rogers Memorial Library for an annex after the library moved to a new building on the edge of town. The library was acquired for $1.1 million from more than $3 million donated by Carroll Petrie for the acquisition and renovations.[4]

The buildings were still considered too small for the collection. In 2012 as part of the move to Water Mill the library was sold for $2.875 to Ajax Holding LLC., which has plans to convert the building commercial space and to also restore it. The original Parrish structure is to undergo renovations designed by architect David Rockwell to become the new Southampton Center.[4]

The museum encountered opposition to its plans to modernize and enlarge its historic Jobs Lane complex.[1] In 2005 the Museum purchased a 14-acre (57,000 m2) site in Water Mill, New York for $3.8 million on the site of a former tree nusery[5] immediately adjacent to the Duck Walk Vineyards winery 2.3 miles (3.7 km) from the original location on Jobs Lane, Southampton, for $3.8 million.[2] The museum board’s decision was the new Parrish Museum was not to take the form of an extension of the existing building of 1897, but was to be designed as a new complex on a new and undeveloped site.[6] Chosen from a list of 65 architect candidates, Pritzker Prize winners Herzog & de Meuron were engaged to develop a new building for the site.[2]

The original plan Herzog plan called for an $80 million village [3] 62,974 square foot museum consisting of 30 modest, low-slung buildings,[2] The buildings were to resemble the studios of area painters.[7]

However financing fell apart in the Financial crisis of 2007–2008 and the museum dramatically downsized to be less than a third ($26.2 million) of the original budget.[8][9] The new structure is designed as a gigantic barn[10] 615 feet long and 95 feet wide.[11] It has poured concete walls. The building's footprint is 34,000 square feet.[11] It has a 6,000 square foot porch as well as educational and multi-purpose spaces. Inside, the single-floor museum is structured in a very simple way, with public functions (such as reception, store, and café) to the west, administrative offices and art handling to the east, and the galleries, arrayed in two parallel bars, on either side of a central hall with moveable walls. There are seven galleries, totaling 7,600 square feet, for the permanent collection, and three for temporary exhibitions.[12] All of the galleries are illuminated by daylight that shifts gradually throughout the day and changes with the seasons.[13] The building which parallels the Montauk Highway to the south and the Long Island Rail Road tracks to the north is said to have been situated so it can catch the "Hamptons light" which is said to be a reason for the area's popularity as an artist colony (its location about a mile from the Atlantic Ocean to the south and two miles from the Little Peconic Bay to the north) [14] It officially opened on November 10, 2012. The first temporary exhibit was by Malcolm Morley who has a home in Bellport, New York.[1]

The Parrish holds the largest public collection of William Merritt Chase (over 40 paintings and works on paper) and an extensive archive, including over 1000 photographs relating to the life and work of the artist, in particular, family photographs of summers spent here on the East End.

As portraitist and landscape painter, and as a teacher of art, Chase was unequalled in his day and it was not surprising that when a group of Southampton boosters had the idea of improving the summer resort by establishing an art school, the Shinnecock Hills Summer School of Art, they chose the prominent Mr. Chase to be the first teacher.

The Museum’s collection features paintings from all periods of his work, including the early Still Life with Fruit (1871); works from the famous New York park scenes series, notably Park in Brooklyn (ca. 1887); major studio paintings from the 1880s, such as The Blue Kimono (ca. 1888); and of course, the paintings made during those summers in the Shinnecock Hills, including The Bayberry Bush (ca. 1895).

Fairfield Porter was one of the most important American realist painters from 1949 until his death in 1975. Not coincidentally, these were the years when Porter lived in Southampton, New York, and in 1979 his estate recognized the bond between the artist and the Museum by donating some 250 works to the Parrish collection.

Porter was both a gifted painter and an accomplished writer who produced some of the most lucid art criticism and commentary of the time, notably his reviews for the magazine Art News. He insisted that he painted what he saw rather than what he might assume to be there. Porter painted what he was familiar with—his family and friends and the places he lived and visited, including Southampton, New York and a family-owned island off the coast of Maine where he had summered since childhood.

Writing about the intimate interior paintings of the French artists Vuillard and Bonnard, Porter found that in their work that recorded the ordinary "…the extraordinary is everywhere." An artist who steadfastly maintained a figurative vision, he knew and admired many Abstract Expressionist artists on the East End, especially Willem de Kooning. Porter once wrote: "The realist thinks he knows ahead of time what reality is, and the abstract artist what art is, but it is in its formality that realist art excels, and the best abstract art communicates an overwhelming sense of reality."

The collection also includes a substantial number of prints and drawings, among them works by George Bellows, Marsden Hartley, Larry Rivers, Helen Frankenthaler, and Robert Rauschenberg. In 1982 Paul F. Walter donated drawings by many Minimalist painters and sculptors, including Barry Le Va, Dorothea Rockburne, Mel Bochner, and Jennifer Bartlett. Robert Dunnigan gave the Museum more than 500 etchings in 1976, with prints by many of the American artists who participated in the “painter-etcher” movement of the late nineteenth century. Also in the Museum’s print collection are nearly 200 Japanese woodblock prints presented as part of the Littlejohn bequest. Dating from the nineteenth and twentieth centuries, they provide a contrast to their American counterparts from the same period.

The Museum schedules four or five exhibitions per year. While some recent shows, such as Fairfield Porter: Raw—The Creative Process of an American Master and American Landscapes: Treasures from the Parrish Art Museum, are drawn from the permanent collection, the majority are exhibitions organized by Parrish curators exploring themes and concepts in art. Recent solo shows have included Alice Aycock: Some Stories are Worth Repeating; Jennifer Bartlett: History of the Universe—Paintings 1970–2011; Rackstraw Downes: Onsite Paintings, 1972-2008; Alex Katz: Seeing, Drawing, Making; Roy Lichtenstein: American Indian Encounters; Platform: Maya Lin; Platform: Josephine Meckseper; Jean Luc Mylayne; Alan Shields: Stirring the Waters; Michelle Stuart: Drawn from Nature; and Jack Youngerman: Folding Screen Paintings. Notable among recent group exhibitions are Encouraging American Genius: Master Paintings from the Corcoran Gallery of Art; All the More Real; Sand: Memory, Meaning, and Metaphor; Modern Photographs: The Machine, the Body, and the City; and Damaged Romanticism: A Mirror of Modern Emotion.

The Parrish also has a long tradition of juried exhibitions. For most of the Museum’s history, these exhibitions were open to all artists, who were selected by a panel of three judges. In 2008, in recognition of the Museum’s important mission of celebrating the art of the East End, the format changed. Submissions were limited to artists from eastern Long Island, whose digital entries were reviewed by nine established artists from the region. Each juror gradually narrowed his or her choices until a single selection was made. The nine chosen artists exhibited their work in tandem with the artists who selected them. This format not only focused on the artists of the region but also encouraged interaction among artists at different points in their careers. Artists Choose Artists of the East End will be a recurring program.

After the Parrish moved to its Water Mill location in November 2012, it has 4,600 square feet (430 m2) of exhibition space dedicated to temporary exhibitions and 7,600 square feet (710 m2) for display of the permanent collection.[11] Future shows will focus on Steven and William Ladd; Alan Shields; Jules Feiffer; Joe Zucker; Robert Dash; and Chuck Close.

In an interview for Hamptons Magazine in July, 2012, Sultan said that for the opening in November, 2012, the Parrish will show its first-ever installation featuring art from all periods in the museum’s 2,600-work permanent collection, addng that many works will be completely new to visitors. During the building campaign, the article by Judith H. Dobrzynski said, the museum acquired many more painting and sculptures that will be shown, including a large Louise Nevelson sculpture, Dorothea Rockburne’s "Touchstone" and Rainer Fetting’s "Two Sunsets in East Hampton." Sultan added, "We covet a major Jackson Pollock, and some more great Abstract Expressionism pieces,” she says. “We have some, but it would be nice to have more works by Fischl, Salle, Bleckner, Close, Alice Aycock….”

Past Imperfect: A Museum Looks at Itself. By Donna De Salvo, with essays by Maurice Berger, Alan Wallach, and a contribution by Judith Barry. 1993. The Parrish Art Museum in association with The New Press, New York, New York.